'X Factor' judge Nicole Scherzinger was left in tears after Jahmene Douglas's performance on Saturday's show.
Her act chose to sing Whitney Houston's 'I Look To You', which he dedicated to his older brother Daniel, who died three years after he saved Jahmene from committing suicide.
Tragically Daniel went on to kill himself, telling his younger brother never to stop singing in a heart-breaking suicide note.
Nicole told Jahmene: "What's so special about you is where that voice and that spirit came from… you're just a little angel."
Louis Walsh said: "There's no way you're going back to Asda now," and Tulisa added: "That performance was the next level… I could feel your emotions on stage."
All four remaining acts in the competition performed songs that meant something to them during the semi-final show.
Christopher Maloney sang 'You Raise Me Up' by Josh Groban and dedicated it to his nan.
Nicole told the Liverpudlian: "You have proved that you deserve your place… it was powerful and amazing." And Louis said: "I think you're going to make a great record."
Louis's act Union J performed Labrinth's hit 'Beneath Your Beautiful' and James Arthur sang U2's 'One', dedicating it to his brother.
Jahmene also performed his original audition song, Etta James 'At Last', while Christopher sang Michael Buble's 'I Just Haven't Met You Yet'.Suggest a correction